2. Pedro Alonso Lopez
3. Jeffrey Dahmer
Jeffrey Dahmer is the scariest serial killers of the United States. In his thirteen years, Dahmer killed 17 men and boys. He murdered, rapes, necrophilia, dismemberment and cannibalism. The police discovered very disturbing things in his apartment. Apparently, while he was doing a horrific sexual act, he drills into the alive heads and skulls of his victims. When they died, he either had sex with the bodies or ate pieces of them. He was arrested in 1994 and was beaten to death by a jail inmate.